Audi S8 D4 V8 with some issues

Hello Everyone,

I've just bought an Audi S8 D4 2015 4.0 TFSI with V8 engine last Saturday and have some concerns. It's only over 34000 miles.

After driving 200 miles I noticed the EPC light on the dash. This light only comes when press start button once. It disappears once engine is ON. Is it normal?

Second issue is the fuel consumption. Today I made over 180 miles, driving in Economy mode and average consumption shows between 11 and 12 per 100KM. Mostly driving 60, 70 miles per hour.

It's just taking to much fuel, worried that the EPC could have sth to do with that.

I've another Audi A6 3.0 V6 engine 313 bhp and I spend far less on diesel than for this S8. I know that's the V8 and 4.0 engine with S8, but if I'd drive in dynamic mode it would take far more and actually I could get the same speed that I get with A6. I just feel that there's sth wrong with this car. It had 3 previous owners.

Any ideas or help with this issue or has anybody came accross that kind of problems with S8?

I always wanted to have V8 engine, love that noise, but I can't use it cause of the running cost.

I've seen some Youtube movies which show less fuel consumption with S8 605 bhp versions, so how come that 520 bhp takes more fuel?